<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <link href="./css/index.css" rel="stylesheet">
  <style>
    h1 {
      color: #000;
    }

    svg {
      min-width: 600px;
      min-height: 200px;
      overflow: auto;
    }
  </style>
</head>
<body>
<h1>SVG Gradient</h1>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <defs>
    <radialGradient id="grad1" cx="50%" cy="50%" r="50%" fx="50%" fy="50%">
      <stop offset="0%" style="stop-color:rgb(255,255,255);
      stop-opacity:0"/>
      <stop offset="100%" style="stop-color:rgb(0,0,255);stop-opacity:1"/>
    </radialGradient>
  </defs>
  <ellipse cx="200" cy="70" rx="85" ry="55" fill="url(#grad1)"/>
</svg>

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
  <defs>
    <radialGradient id="grad2" cx="20%" cy="30%" r="30%" fx="50%" fy="50%">
      <stop offset="0%" style="stop-color:rgb(255,255,255); stop-opacity:0"/>
      <stop offset="100%" style="stop-color:rgb(0,0,255);stop-opacity:1"/>
    </radialGradient>
  </defs>
  <ellipse cx="200" cy="70" rx="85" ry="55" fill="url(#grad2)"/>
</svg>
<!--<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>-->
<script src="./js/d3.v4.min.js"></script>
<script src="./js/svg.js"></script>
</body>
</html>